1. Field of the Invention
The invention relates to a clutch disk assembly and a clutch device. More specifically, the present invention relates to a clutch disk assembly in which a clutch disk is fixed to outer peripheral portions of a pair of plate members that are fixed together, as well as a clutch device.
2. Background Information
A conventional clutch disk assembly used in a clutch of a vehicle generally has a clutch function and a damper function. The clutch function provides that the assembly engages and disengages a flywheel. The damper function provides that vibrations supplied from the flywheel are absorbed or damped.
A conventional clutch disk assembly includes a pair of input plates, an output hub, and coil springs. The pair of input plates axially oppose each other. The output hub is integrally provided with a radial flange. The coil springs elastically couple the input plates to the output hub in a circumferential direction. The coil springs are provided to realize the damper function and absorb vibrations from the flywheel. The paired input plates have radially outer portions that are fixed together. Thus, the paired input plates are arranged to rotate together. A plurality of stud pins are arranged in circumferentially spaced positions to fix the radially outer portions together. Opposite ends of each stud pin are fixed to the input plates by swaging or crimping, respectively. A clutch disk is fixed to a radially outer portion of one of the paired input plates by a plurality of rivets. The clutch disk is configured to be pressed against a friction surface of the flywheel by a pressure plate of the clutch cover assembly. The clutch disk is formed of, e.g., two friction facings and a cushioning plate arranged therebetween. The friction facing has an annular plate-like form, and is arranged radially outside fixing portions (e.g., stud pins) of the paired input plates described above. Therefore, if the position of the fixing portion of the input plate pair is shifted radially outward from the conventional position for the sake of design, the inner diameter of the clutch disk, and as a consequence, the inner diameter of the friction facing are increased.
In view of the above, there exists a need for a clutch disk assembly and clutch device that overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
An object of the invention is to suppress an increase in an inner diameter of a friction facing, which may be caused by fixing portions of paired plates of a clutch disk assembly.
According to a first aspect of the invention, a clutch disk assembly that is arranged to be coupled to a flywheel of an engine, includes a friction facing, a pair of plate members, a hub, and an elastic member. The friction is facing arranged near the flywheel. The plate members are axially spaced from each other and have fixing portions for fixing radially outer portions of the plate members together. The elastic member elastically couples the paired plate members to the hub in a rotating direction. The fixing portion extends radially outside of an inner periphery of the friction facing. According to this clutch disk assembly, the fixing portion has a portion located radially outside the inner periphery of the friction facing so that the fixing portion does not increase the inner diameter of the friction facing.
A clutch disk assembly according to a second aspect of the present invention is the assembly of the first aspect further having a feature such that the fixing portions are formed in a plurality of circumferentially spaced positions on outer peripheries of the paired plate members.
A clutch disk assembly according to a third aspect of the present invention is the assembly of the first or second aspect further having a feature such that one of the paired plate members near the flywheel has a main body and a coupling portion. The coupling portion preferably extends from the outer periphery of the main body toward the other plate member and is coupled to the other plate member. The coupling portion has an axial extension and the fixing portion that extends radially outward from the axial extension. In this clutch disk assembly, the fixing portion of the coupling portion extends radially outward from the axial extension so that the required manufacturing steps can be fewer than those of a conventional structure having a radially outward fixing portion.
According to a fourth aspect of the present invention, a clutch device includes the clutch disk assembly of one of the first to third aspects, and a clutch cover assembly having a pressure plate for pressing the friction facing against the flywheel. The fixing portion extends further radially outside of the inner periphery of a pressing surface of the pressure plate.
According to a fifth aspect of the present invention, a clutch device or clutch disk assembly of any one of the first to fourth aspects further has a feature such that the pressure plate has a first inner peripheral surface and a second inner peripheral surface. The first inner peripheral surface is located on the friction facing side. The second inner peripheral surface is located on a side remote from the friction facing and has a diameter larger than that of the first inner peripheral surface. The radially outer end of the fixing portion is located radially outside the first inner peripheral surface, and is close to the second inner peripheral surface.
According to a sixth aspect of the present invention, a clutch device having a clutch disk assembly of any one of the first to fourth aspects, further has a feature such that the pressure plate has an annular main body and an annular portion extending radially inward from a portion on the friction facing side of the inner peripheral portion of the annular main body. The fixing portion is located on a side of the annular portion remote from the friction facing.
According to a seventh aspect of the present invention, a clutch device or clutch disk assembly of the sixth aspect further has a feature such that the annular portion is provided with a recess allowing axial movement of the fixing portion through the recess. According to this clutch device or clutch disk assembly, the fixing portion moves through the recess of the annular portion of the pressure plate when attaching the clutch cover assembly to the flywheel. This facilitates an attaching operation of the clutch cover assembly.
These and other objects, features, aspects, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, when taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.